Amino acids and biogenic amines during spontaneous malolactic fermentation in Tempranillo red wines

This paper examines the changes undergone by the nitrogenated fraction of wine during malolactic fermentation (MLF) produced by the indigenous microbiota in 16 industrial-scale vinifications at technologically well-equipped wineries. Statistically significant increases (between 5% and 35%) were found in 15 of the 24 amino acids analyzed; decreases (between 4% and 29%) were found only in four. The biogenic amines histamine, tyramine and putrescine increased by between 106% and 174%, but histamine final concentrations in wine were not too high, under the limit of 10 mg/L established by Switzerland. There was a non-significant increase of 2.0–2.3 μg/L in ethyl carbamate.